diff mbox series

[v9,5/8] gpio: Initial support for ROHM bd70528 GPIO block

Message ID 8334d6064575249e871e88aa6057b134795232e3.1550063882.git.matti.vaittinen@fi.rohmeurope.com
State Superseded
Headers show
Series support ROHM BD70528 PMIC | expand

Commit Message

Matti Vaittinen Feb. 13, 2019, 1:34 p.m. UTC
ROHM BD70528 PMIC has 4 GPIO pins. Allow them to be
controlled by GPIO framework.

IRQs are handled by regmap-irq and GPIO driver is not
aware of the irq usage.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/Kconfig        |  11 +++
 drivers/gpio/Makefile       |   1 +
 drivers/gpio/gpio-bd70528.c | 232 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 244 insertions(+)
 create mode 100644 drivers/gpio/gpio-bd70528.c

Comments

Linus Walleij Feb. 14, 2019, 8 a.m. UTC | #1
On Wed, Feb 13, 2019 at 2:34 PM Matti Vaittinen
<matti.vaittinen@fi.rohmeurope.com> wrote:

> ROHM BD70528 PMIC has 4 GPIO pins. Allow them to be
> controlled by GPIO framework.
>
> IRQs are handled by regmap-irq and GPIO driver is not
> aware of the irq usage.
>
> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

(...)

Just spotted this:

> +#include <linux/gpio/driver.h>
> +#include <linux/gpio.h>

A driver should only need <linux/gpio/driver.h>
the <linux/gpio.h> should not be used at all in new code,
it is a legacy header.

> +static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
> +                                  unsigned long config)
> +{
> +       struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
> +
> +       switch (pinconf_to_config_param(config)) {
> +       case PIN_CONFIG_DRIVE_OPEN_DRAIN:
> +               return regmap_update_bits(bdgpio->chip.regmap,
> +                                         GPIO_OUT_REG(offset),
> +                                         BD70528_GPIO_DRIVE_MASK,
> +                                         BD70528_GPIO_OPEN_DRAIN);
> +               break;
> +       case PIN_CONFIG_DRIVE_PUSH_PULL:
> +               return regmap_update_bits(bdgpio->chip.regmap,
> +                                         GPIO_OUT_REG(offset),
> +                                         BD70528_GPIO_DRIVE_MASK,
> +                                         BD70528_GPIO_PUSH_PULL);
> +               break;
> +       case PIN_CONFIG_INPUT_DEBOUNCE:
> +               return bd70528_set_debounce(bdgpio, offset,
> +                                           pinconf_to_config_argument(config));
> +               break;
> +       default:
> +               break;
> +       }
> +       return -ENOTSUPP;
> +}

BTW I just merged code from Thomas Petazzoni that make it possible to
also support pull-up and pull-down from GPIO here if you want to enable
it.

Yours,
Linus Walleij
Matti Vaittinen Feb. 14, 2019, 8:29 a.m. UTC | #2
Thanks a bunch Linus,

On Thu, Feb 14, 2019 at 09:00:33AM +0100, Linus Walleij wrote:
> On Wed, Feb 13, 2019 at 2:34 PM Matti Vaittinen
> <matti.vaittinen@fi.rohmeurope.com> wrote:
> 
> > ROHM BD70528 PMIC has 4 GPIO pins. Allow them to be
> > controlled by GPIO framework.
> >
> > IRQs are handled by regmap-irq and GPIO driver is not
> > aware of the irq usage.
> >
> > Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
> > Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> (...)
> 
> Just spotted this:
> 
> > +#include <linux/gpio/driver.h>
> > +#include <linux/gpio.h>
> 
> A driver should only need <linux/gpio/driver.h>
> the <linux/gpio.h> should not be used at all in new code,
> it is a legacy header.

Allright. I'll do v10 and drop the header. Thanks for pointing this out

> > +static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
> > +                                  unsigned long config)
> > +{
> > +       struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
> > +
> > +       switch (pinconf_to_config_param(config)) {
> > +       case PIN_CONFIG_DRIVE_OPEN_DRAIN:
> > +               return regmap_update_bits(bdgpio->chip.regmap,
> > +                                         GPIO_OUT_REG(offset),
> > +                                         BD70528_GPIO_DRIVE_MASK,
> > +                                         BD70528_GPIO_OPEN_DRAIN);
> > +               break;
> > +       case PIN_CONFIG_DRIVE_PUSH_PULL:
> > +               return regmap_update_bits(bdgpio->chip.regmap,
> > +                                         GPIO_OUT_REG(offset),
> > +                                         BD70528_GPIO_DRIVE_MASK,
> > +                                         BD70528_GPIO_PUSH_PULL);
> > +               break;
> > +       case PIN_CONFIG_INPUT_DEBOUNCE:
> > +               return bd70528_set_debounce(bdgpio, offset,
> > +                                           pinconf_to_config_argument(config));
> > +               break;
> > +       default:
> > +               break;
> > +       }
> > +       return -ENOTSUPP;
> > +}
> 
> BTW I just merged code from Thomas Petazzoni that make it possible to
> also support pull-up and pull-down from GPIO here if you want to enable
> it.

Thanks for heads up Linus! I'll check it out although I don't want to
add up more changes in this series... But my initial feeling is that
this will deserve another patch (set) when initial support for BD70528
is available. (This answer is not locked, it may be I will fit the
change in this series if I am not buried under other duties ;] )

Br,
	Matti Vaittinen
Matti Vaittinen Feb. 14, 2019, 12:38 p.m. UTC | #3
Hello Linus,

On Thu, Feb 14, 2019 at 10:29:01AM +0200, Matti Vaittinen wrote:
> Thanks a bunch Linus,
> 
> On Thu, Feb 14, 2019 at 09:00:33AM +0100, Linus Walleij wrote:
> > On Wed, Feb 13, 2019 at 2:34 PM Matti Vaittinen
> > <matti.vaittinen@fi.rohmeurope.com> wrote:
> > 
> > Just spotted this:
> > 
> > > +#include <linux/gpio/driver.h>
> > > +#include <linux/gpio.h>
> > 
> > A driver should only need <linux/gpio/driver.h>
> > the <linux/gpio.h> should not be used at all in new code,
> > it is a legacy header.
> 
> Allright. I'll do v10 and drop the header. Thanks for pointing this out

It seems to me the GPIOF_DIR_XXX are defined in linux/gpio.h. It would
be nice to refer to these flags when interpreting the return value
from the bd70528_get_direction (used in bd70528_gpio_get) - and actually
it might be nice to use those as a return value from bd70528_get_direction.

But I'll go with raw values for now and leave possible definition
moving/header refactoring to you who know the direction of code better :)

Br,
	Matti Vaittinen
diff mbox series

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b5a2845347ec..c82187648630 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -962,6 +962,17 @@  config GPIO_ARIZONA
 	help
 	  Support for GPIOs on Wolfson Arizona class devices.
 
+config GPIO_BD70528
+	tristate "ROHM BD70528 GPIO support"
+	depends on MFD_ROHM_BD70528
+	help
+	  Support for GPIOs on ROHM BD70528 PMIC. There are four GPIOs
+	  available on the ROHM PMIC in total. The GPIOs can also
+	  generate interrupts.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called gpio-bd70528.
+
 config GPIO_BD9571MWV
 	tristate "ROHM BD9571 GPIO support"
 	depends on MFD_BD9571MWV
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 37628f8dbf70..6f12c83598fc 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -34,6 +34,7 @@  obj-$(CONFIG_GPIO_ATH79)	+= gpio-ath79.o
 obj-$(CONFIG_GPIO_ASPEED)	+= gpio-aspeed.o
 obj-$(CONFIG_GPIO_RASPBERRYPI_EXP)	+= gpio-raspberrypi-exp.o
 obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o
+obj-$(CONFIG_GPIO_BD70528) 	+= gpio-bd70528.o
 obj-$(CONFIG_GPIO_BD9571MWV)	+= gpio-bd9571mwv.o
 obj-$(CONFIG_GPIO_BRCMSTB)	+= gpio-brcmstb.o
 obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-bd70528.c b/drivers/gpio/gpio-bd70528.c
new file mode 100644
index 000000000000..c00d5d67dd74
--- /dev/null
+++ b/drivers/gpio/gpio-bd70528.c
@@ -0,0 +1,232 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 ROHM Semiconductors
+// gpio-bd70528.c ROHM BD70528MWV gpio driver
+
+#include <linux/gpio/driver.h>
+#include <linux/gpio.h>
+#include <linux/mfd/rohm-bd70528.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define GPIO_IN_REG(offset) (BD70528_REG_GPIO1_IN + offset*2)
+#define GPIO_OUT_REG(offset) (BD70528_REG_GPIO1_OUT + offset*2)
+
+struct bd70528_gpio {
+	struct rohm_regmap_dev chip;
+	struct gpio_chip gpio;
+};
+
+static int bd70528_set_debounce(struct bd70528_gpio *bdgpio,
+				unsigned int offset, unsigned int debounce)
+{
+	u8 val;
+
+	switch (debounce) {
+	case 0:
+		val = BD70528_DEBOUNCE_DISABLE;
+		break;
+	case 1 ... 15:
+		val = BD70528_DEBOUNCE_15MS;
+		break;
+	case 16 ... 30:
+		val = BD70528_DEBOUNCE_30MS;
+		break;
+	case 31 ... 50:
+		val = BD70528_DEBOUNCE_50MS;
+		break;
+	default:
+		dev_err(bdgpio->chip.dev,
+			"Invalid debouce value %u\n", debounce);
+		return -EINVAL;
+	}
+	return regmap_update_bits(bdgpio->chip.regmap, GPIO_IN_REG(offset),
+				 BD70528_DEBOUNCE_MASK, val);
+}
+
+static int bd70528_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
+	int val, ret;
+
+	/* Do we need to do something to IRQs here? */
+	ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val);
+	if (ret) {
+		dev_err(bdgpio->chip.dev, "Could not read gpio direction\n");
+		return ret;
+	}
+
+	return !(val & BD70528_GPIO_OUT_EN_MASK);
+}
+
+static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
+				   unsigned long config)
+{
+	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+		return regmap_update_bits(bdgpio->chip.regmap,
+					  GPIO_OUT_REG(offset),
+					  BD70528_GPIO_DRIVE_MASK,
+					  BD70528_GPIO_OPEN_DRAIN);
+		break;
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		return regmap_update_bits(bdgpio->chip.regmap,
+					  GPIO_OUT_REG(offset),
+					  BD70528_GPIO_DRIVE_MASK,
+					  BD70528_GPIO_PUSH_PULL);
+		break;
+	case PIN_CONFIG_INPUT_DEBOUNCE:
+		return bd70528_set_debounce(bdgpio, offset,
+					    pinconf_to_config_argument(config));
+		break;
+	default:
+		break;
+	}
+	return -ENOTSUPP;
+}
+
+static int bd70528_direction_input(struct gpio_chip *chip, unsigned int offset)
+{
+	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
+
+	/* Do we need to do something to IRQs here? */
+	return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
+				 BD70528_GPIO_OUT_EN_MASK,
+				 BD70528_GPIO_OUT_DISABLE);
+}
+static void bd70528_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			     int value)
+{
+	int ret;
+	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
+	u8 val = (value) ? BD70528_GPIO_OUT_HI : BD70528_GPIO_OUT_LO;
+
+	ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
+				  BD70528_GPIO_OUT_MASK, val);
+	if (ret)
+		dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value);
+}
+
+static int bd70528_direction_output(struct gpio_chip *chip, unsigned int offset,
+				    int value)
+{
+	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
+
+	bd70528_gpio_set(chip, offset, value);
+	return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
+				 BD70528_GPIO_OUT_EN_MASK,
+				 BD70528_GPIO_OUT_ENABLE);
+}
+
+#define GPIO_IN_STATE_MASK(offset) (BD70528_GPIO_IN_STATE_BASE << offset)
+
+static int bd70528_gpio_get_o(struct bd70528_gpio *bdgpio, unsigned int offset)
+{
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val);
+	if (!ret)
+		ret = !!(val & BD70528_GPIO_OUT_MASK);
+	else
+		dev_err(bdgpio->chip.dev, "GPIO (out) state read failed\n");
+
+	return ret;
+}
+
+static int bd70528_gpio_get_i(struct bd70528_gpio *bdgpio, unsigned int offset)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(bdgpio->chip.regmap, BD70528_REG_GPIO_STATE, &val);
+
+	if (!ret)
+		ret = !(val & GPIO_IN_STATE_MASK(offset));
+	else
+		dev_err(bdgpio->chip.dev, "GPIO (in) state read failed\n");
+
+	return ret;
+}
+
+static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	int ret = -EINVAL;
+	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
+
+	/*
+	 * There is a race condition where someone might be changing the
+	 * GPIO direction after we get it but before we read the value. But
+	 * application design where GPIO direction may be changed just when
+	 * we read GPIO value would be pointless as reader could not know
+	 * whether the returned high/low state is caused by input or output.
+	 * Or then there must be other ways to mitigate the issue. Thus
+	 * locking would make no sense.
+	 */
+	ret = bd70528_get_direction(chip, offset);
+	if (ret == GPIOF_DIR_OUT)
+		ret = bd70528_gpio_get_o(bdgpio, offset);
+	else if (ret == GPIOF_DIR_IN)
+		ret = bd70528_gpio_get_i(bdgpio, offset);
+	else
+		dev_err(bdgpio->chip.dev, "failed to read GPIO direction\n");
+
+	return ret;
+}
+
+static int bd70528_probe(struct platform_device *pdev)
+{
+	struct bd70528_gpio *bdgpio;
+	struct bd70528 *bd70528;
+	int ret;
+
+	bd70528 = dev_get_drvdata(pdev->dev.parent);
+	if (!bd70528) {
+		dev_err(&pdev->dev, "No MFD driver data\n");
+		return -EINVAL;
+	}
+
+	bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),
+				    GFP_KERNEL);
+	if (!bdgpio)
+		return -ENOMEM;
+	bdgpio->chip.dev = &pdev->dev;
+	bdgpio->gpio.parent = pdev->dev.parent;
+	bdgpio->gpio.label = "bd70528-gpio";
+	bdgpio->gpio.owner = THIS_MODULE;
+	bdgpio->gpio.get_direction = bd70528_get_direction;
+	bdgpio->gpio.direction_input = bd70528_direction_input;
+	bdgpio->gpio.direction_output = bd70528_direction_output;
+	bdgpio->gpio.set_config = bd70528_gpio_set_config;
+	bdgpio->gpio.can_sleep = true;
+	bdgpio->gpio.get = bd70528_gpio_get;
+	bdgpio->gpio.set = bd70528_gpio_set;
+	bdgpio->gpio.ngpio = 4;
+	bdgpio->gpio.base = -1;
+#ifdef CONFIG_OF_GPIO
+	bdgpio->gpio.of_node = pdev->dev.parent->of_node;
+#endif
+	bdgpio->chip.regmap = bd70528->chip.regmap;
+
+	ret = devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio,
+				     bdgpio);
+	if (ret)
+		dev_err(&pdev->dev, "gpio_init: Failed to add bd70528-gpio\n");
+
+	return ret;
+}
+
+static struct platform_driver bd70528_gpio = {
+	.driver = {
+		.name = "bd70528-gpio"
+	},
+	.probe = bd70528_probe,
+};
+
+module_platform_driver(bd70528_gpio);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("BD70528 voltage regulator driver");
+MODULE_LICENSE("GPL");